Method of destroying a weed



United States Patent 3,352,663 METHOD OF DESTROYING A WEED Heinz Eberhard Freund, Friedrich Arndt, and Reinhart Rusch, Berlin, Germany, assignors to Schering, A.G., Berlin, Germany No Drawing. Filed June 1, 1964, Ser. No. 371,824 Claims priority, application Germany, June 26, 1963, Sch 33,461 10 Claims. (CI. 71-25) This invention relates to active herbicidal agents, and more particularly to selective herbicides.

A primary object of the invention is the selective destruction of weeds from mingled stands of said weeds and of crop plants without damaging the latter.

Another object is the provision of compounds which combine herbicidal effectiveness against a wide variety of weeds with harmless affects toward a wide variety of crop plants.

More specifically, the invention aims to provide effective weed killing agents which do not damage crop plants when applied to portions of the crop plants above ground, particularly the leaves.

Heretofore, there have been many otherwise excellent known herbicides which are deleterious to crop plants when they come into contact with the leaves of the same.

' trum of weeds, and harmless'to an equally wide spectrum of crop plants. The selective herbicidal agents of the invention have the formula I HCH X wherein X may be hydrogen, a halogen, lower alkyl, lower alkoxy, N or W-trifiuoro-(lower) alkyl, and Y is hydrogema halogen, or lower alkyl,

The optimum rate of application of the he C II C :bicidal agents ofthe invention varies with their chemical composition,

the nature of the crop plants and weeds to be treated, and

the stage of development oftheweeds and crops As a general rule, 2 to 5 kg. of the active agentwhen applied to one hectare (ha.) produce the desired result. (1 hectare is equal to 2.471 acres.) Many crop plants, however, readily tolerate as much as kg./ha. of the most active agents without suffering damage. The good tolerance of many crop plants for the selective herbicides of the invention makes it possible to use them on multiple crops, for example, a cereal crop having an undercrop of clover or grass. 1

The herbicidal agents of the invention maybe applied by all conventional methods in all forms in which weed killers are normally applied. Compositions containing a herbicidal agent of the invention as the active ingredient may be solid or liquid. The solid compositions-may consist of loose fine powders or of granular particles. The liquid compositions may be solutions, emulsions, or suspensions of the active agents. The compositions may further contain liquid or solid inert carriers and diluents, and

- also surface active agents as is usual in this art.

Suitable liquid carriers and diluents are water, mineral oil and other organic solvents such as xylene, cyclohexanol, cyclohexanone, chloroform, carbon tetrachloride, di-

methylformamide, dimethylsulfoxida and the like. Solid Patented Nov. 14, 1967 fonic acids, sulfonated acid amides and their salts, polyethoxylated amines and alcohols.

Each compound of the invention may be used as the sole active agent in a herbicidal composition, or it may be combined with other compounds of the invention, with other crop protecting agents or pesticides, and with such other agricultural chemicals as fertilizers.

The concentration of the herbicidal agents of the invention in the various types of compositions which readily suggest themselves to those skilled in the art may vary so widely, that it is not possible to provide general rules which would be meaningful under the many conditions of use which are affected by the nature 'of the composition, such as, the manner in which it is prepared, the manner in which it is to be applied, the desired result, the type and condition of the weeds to be destroyed, and the like.

In view of the state of this art, those who are skilled in this field will find sufiicient guidance in the examples of specific applications which will presently be described.

The compounds of the invention are prepared from 2- furanoylchloride and aniline or its derivatives in the presence of an acid acceptor in the manner commonly em ployed in the preparation of acyl'anilides.

The following examples are further illustrative of this invention, and it will be understood that the invention is not limited thereto.

Example 1 Plants of mustard (Sinapis sp.), corn, and wheat were uniformly sprayed in a greehouse test with 2% aqueous suspensions of herbicides of the invention. The plants were 'after germination and the spray was mainly applied to their parts above ground. The results observed after 14 days were evaluated on an arbitrary scale on which 0 CH-CH X ll H 1 CH C CONH-C0H4\ O, .Y

- and only the substituents X and Y are identified in the table.

- TABLE 1 Substituent Efieet on- X Y Mustard Corn Wheat H H 10 2 v1 2-01 B 3 0 0 3-01 H 10 0 '0 1 4-Cl H 10 0 '0 2-Ol 5-01 10 0 0 3-01 4-Cl 10 0 0 4-13! B 5 0 0 2-CH:- H 9 0 01 3-GHa- H 10 Y 0 0 4-011; H' 10 1., o. ""2-CH: 4-CH: 3 0 0 2-CH: 5-011: 10 0 0-1 2-CH: 4-01 9v 0 0 a 3-01 4-CH3 9-10 1 0 3-013: H 9-10 0 0 2-N0z H 6 0 0 3-NO: H 7 0 0 4-N0z H 6 0 0 Q2-Ethoxy H 3 0 0 i Methoxy H 10 0 0 4-Ethoxy H 6 0 0 The herbicides of the invention cause very little damage, if any, to the crop plants corn and wheat in amounts which entirely, or almost entirely destroy the mustard weed. Even the least effective herbicides of the 4 Example 4 The representative herbicides of the invention listed in Table 4 were applied to four types of cereal crops having red clover as an undercrop. The herbicides were apinventiqn .When employed in the amourlts of this l D pliedas aqueous suspensions at a rate of kilograms of cause slgmficant damage to the weed whfle not afiectm'g active agent in 1000 liters water per hectare. Although the crop Plants toameasmable extent the rate of application was more than three times that Example 2 of Example 3, and more than adequateto deal with the weeds enumerated there, the cereal crops were not noticesoll seedeid wlthf g gl f gg w gg 10 ably atfected. These crops were barley, oats, rye, and (ms Q F F 5 er i f 1 a wheat. The very slight etfects on the red clover, if any, germmatlon 0 e mus at e e S O 6 Spr y are listed in Table 4. These results are closely similar to treatment were evaluated 14 days later in the manner dethose obtained with grass undercrops scribed in Example 1. The results obtained are tabulated in Table 2 in the same manner as in Table 1. 15 TABLE 4 TABLE 2 Substituent Etffictdon B Substituent Effect on X Y clover Mustard X Y H H 1 Y re s 12 3-01 H 1-2 2-01 5-01 2-3 3701 M31 0 2-011: H 9 ii-GHa H 2-3 2-CH; 4-CHs 5 H 20H: 5-CHa 10 2-0131 4-01 6-7 t-Methoxy H 6-7 xamp e 5 The use of emulsified herbicides is not new, and the A$ 1S P from i the hefblcldal compounds "i well known methods for preparing liquid herbicidal comeirective 1n damaging or destroying weedplants Whlch positions in which the, active agent is present in a colemerge from 5011 SuPerficlauY treated Wlth the loidally dispersed liquid phase are generally applicable p to the herbicides of this invention. The following for- Example 3 mulation has been found to be particularly well adapted Suspensions of the herbicidal compounds of the inven- 9 compounds- Thqlngredlfints mlXed y agltation listed in Table 3 were sprayed on crop plants and lion-The Percentages lfldlcated are by Weight! on weeds infesting the crops. The suspensions were ap- Percent plied at a rate of 800 liters per hectare, and contained 3 Herbicidal agent 10 kilograms of the active agent listed per 800 liters. The Xylene 70 results achieved were evaluated in the manner described Dimethylformamide 15 in Example 1. 40 Calcium dodecylbenzene-sulfonate (emulsifier) 5 lg i f' gfigi zi plants are Identified m Table by The above solution formed emulsifies readily when 1 combined with water. Corn C Example 6 y g A solid composition containing the herbicidal com- Oniong 0 pounds of the invention is readily prepared from the fol- Tomatoes To lowing ingredients by grinding in a ball milk, Stellaria media St Percent Galinsoga parv. G Herbicidal agent 20 Sinapis sp. Si Attaclay Urtica urens U Calcium lignosulfonate 8 Senecia vulg. Se Sodium beta-(oleylmethylamino ethanesulfonate (wet- Matricaria chamomilla M ting agent) 2 TABLE 3 Substituent Efieet on X Y 0 W Tu o lTo St G s1 U Se M H H 0 0 0 0 0 10 1o 10 3-01 H 0 o 0 0 1 a 9 10 4-01 H o 0 o o o 7 7 9 so] 4-01 0 0 0 o 0 2 s 7 arm H 0 0 0 0 0 10 9 s 4-0218 H 0 0 0 0 0 4 9 7 3-01- 4-CH3 0 o 0 o 0 7 4 5 -Methoxy H 0 0 0 0 0 9 9 8 3-015; o 0 o a 4 6 Not all compounds tested were applied to all weeds as indicated by dashes in Table 3, but the results of this field test fully support the conclusions drawnfrom the more limited greenhouse tests. The lack of harmful effects on the varied crops is as surprising as the deleterio s etfects on a wide variety of weeds.

The powder mixture obtained readily disperses in water, and the dispersion or suspension obtained is suitable foruse'as described'in Examples 1 to 3. It may be diluted with solid carriers and applied as a dust.

While the invention has been described with particular reference tospecific embodiments, it is to be underaoam s wherein X is a member of the group consisting of hydrogen, halogen, nitro, lower alkyl, lower alkoxy, and wtrifluoro-(lower)-alkyl, and Y is a member of the group consisting of hydrogen, halogen, and lower alkyl.

2. A method as set forth in claim 1, wherein at least one of said X and Y is methyl.

3. A method as set forth in claim 1, wherein at least one of said X and Y is chlorine.

4. A method as set forth in claim 1, wherein X is bromine.

5. A method as set forth in claim 1, wherein X is methoxy.

6. A method as set forth in claim 1, wherein X is ethoxy.

7. A method as set forth in claim 1, wherein X is trifluoromethyl.

8. A method as set forth in claim 1, wherein X is the nitro radical.

9. A method of destroying a weed which comprises applying to the surface of soil containing a seed of said weed prior to emergence of said weed from said soil a herbicidal amount of a compound having the formula wherein X is a member of the group consisting of hydrogen, halogen, nitro, lower alkyl, lower alkoxy, and w-trifluro flower) -alkyl, and Y is a member of the group consisting of hydrogen, halogen, and lower alkyl.

10. A method of protecting a crop from infesting weeds which comprises applying to portions of said crop and of said weeds above ground a herbicidal amount of an active agent, said amount being smaller than an amount which would substantially damage said crop, said active agent being a compound having the formula CH-CH X 211 JCONH wherein X is a member of the group consisting of hydrogen, halogen, nitro, lower alkyl, lower alkoxy, and w-trifluro-(lower)-alkyl, and Y is a member of the group consisting of hydrogen, halogen, and lower alkyl.

References Cited UNITED STATES PATENTS 3,266,883 8/1966 Leon et a1. 712.5

LEWIS GOTTS, Primary Examiner.

JAMES O. THOMAS, JR., Examiner.

G. HOLLRAH, Assistant Examiner. 

1. A METHOD OF DESTROYING A WEED WHICH COMPRISES APPLYING TO PORTIONS OF SAID WEED ABOVE GROUND A HERBICIDAL AMOUNT OF A COMPOUND HAVING THE FORMULA 